Camera control based on rigid body dynamics for virtual environments

摘要

Desktop virtual environments (VEs) are an attractive choice for low-cost virtual reality systems. However, the level of virtual presence - the subjective sensation of perceiving oneself immersed within an environment - that desktop VEs offer is lower than immersive ones. There exist approaches that try to reduce the gap between the level of presence in these two types of VEs. For instance, to improve the interaction aspect by providing an environment that supports physically based behavior or to display high quality graphics that increases the overall scene realism. Most of these approaches have been employed in the design of desktop VEs, but often lacked a formal evaluation of their real impact on the level of presence afforded. This paper presents our work and research findings on developing a model to control camera travel based on rigid body dynamics. A physics engine simulates the dynamics involved in altering the cameras physical parameters - such as forces, torques, tensor of inertia - which, in turn, controls viewpoint orientation and locomotion. Our aim was twofold: to propose a camera whose movement behaviors were easy to program, and; to engage users of a desktop VE in a richer interaction experience capable of raising their level of presence. We designed an experimental study with a group of volunteers and measured their performance in controlling the camera as well as their reported virtual presence using the Witmer and Singers Presence Questionnaire.